1. Field of the Invention
The present invention relates to insertion apparatuses for placing various devices into a pipeline of flowing gaseous or liquid products and, more particularly, to insertion apparatuses for the insertion and manipulation and/or operation of various devices within the pipeline.
2. Description of the Prior Art
Pipelines carry flowing gaseous or liquid product from one place to another. In many instances it is desirable, if not necessary, to measure, sample or generate data from such flowing product. It is also desirable to control flow such as by regulators or valves. This measurement or flow control can be accomplished by inserting a measuring device, sensor, valve, plug, or various other types of devices into the flow of product within the pipeline. In order to enable such insertion, pipelines are normally fitted with tees. The tees provide an opening into the pipeline and generally a mounting flange or fitting.
One exemplary type of measurement is flow volume as measurable by a turbine flow meter. Another type of measurement is pressure as measurable by a pressure sensor. Since the total value of the product flowing within the pipeline is, in part, dependent on the temperature of the flowing material, sometimes a thermometer is utilized. Still other types of devices that require insertion into the pipeline are sampler devices, regulator valves, orifices and flow diffusers.
It is known to be able to insert such devices into the pipeline by using an insertion apparatus, even under pressure conditions, through a tee. The insertion apparatus is mounted onto the mounting flange or fitting of the tee. The device to be inserted is carried by the insertion apparatus for selective insertion into the pipeline through the tee.
Such an insertion apparatus is described in U.S. Pat. No. 4,177,676 issued to Robert H. Welker on Dec. 11, 1979. The ""676 patent describes a hydraulically operated meter mounting mechanism that is adapted to insert and position a meter transducer in a high pressure environment such as a pipeline. The meter mounting mechanism utilizes a single, movable piston structure having a central, hollow piston rod that reciprocates within the cylinder portion of the piston structure. The piston rod extends beyond the cylinder portion and carries the meter transducer. Wires from the meter transducer may be fed through the piston rod. The piston rod may be selectively locked against rotation by a locking mechanism.
Another insertion apparatus is described in U.S. Pat. No. 4,346,611 issued to Robert H. Welker on Aug. 31, 1982. The ""611 patent describes an insertion apparatus especially adapted to insert a probe into the pipeline. The insertion apparatus includes a single cylinder/piston arrangement to which is coupled a piston rod. The probe is attached to one end of the piston rod external of the cylinder. Pressure from the pipeline is directed into the piston to position the probe into the pipeline.
Still another insertion apparatus is described in U.S. Pat. No. 4,631,967 issued to Robert H. Welker on Dec. 30, 1986. The ""967 patent describes an automatic insertion apparatus that will insert a portion of a piston rod into a pressurized fluid pipeline, usually an end of the piston rod to which is attached a measuring device. The piston rod is actuated by a single cylinder/piston, mounted on the pipeline. Reciprocating movement of the piston rod selectively places the measuring device into the pressurized fluid pipeline flow.
While there are examples in the prior art of insertion apparatuses, such apparatuses perform only a single task, namely, the simple insertion and retraction of the measuring device or sensor into and from the pipeline. There are times where it may be desirable to perform another task once the device or sensor has been inserted into or retracted from the pipeline. For instance, it may be necessary to insert then expand a plug in the pipeline in order to stop or control product flow. Additionally, it may be necessary to insert a device such as a miniature video camera into the pipeline, then activate a switch on the device or perform another function relative to the device. Also, it may be desirable to insert a capsule device, having a protective capsule around a sensitive device, into the pipeline, then open the capsule to expose the device.
In order to perform a xe2x80x9cdualxe2x80x9d task or operation, the prior art utilized a hand crank device to insert a device into the pipeline and then perform the next operation. Such is not efficient and does not allow for remote control, which for safety reasons is often desirable.
It is thus an object of the present invention to provide an insertion device that is capable of performing two independent operations, insertion/retraction and then manipulation once inserted.
A pipeline insertion/probe device is adapted to perform a first and second operation upon an inserted object. The insertion device is characterized by a dual coaxial cylinder/piston structure with dual coaxial, reciprocating hollow shafts. The shafts may be actuated by their respective pistons independently of each other. A primary cylinder and piston structure carries an object to be inserted into the pipeline by its shaft, while a secondary cylinder and piston structure allows a second operation on the inserted object through its shaft. The secondary cylinder and piston structure is coupled to and carried by the primary piston to move therewith.
More particularly, the primary cylinder, adapted to be attached to a pipeline, has a first hollow shaft that is fixedly attached to the primary piston, and is adapted to extend into the interior of the pipeline upon selective movement of the primary piston. The first hollow shaft is retractable from the interior of the pipeline upon selective movement of the primary piston. The secondary cylinder is fixedly attached to the primary piston by a second hollow shaft that extends from the primary cylinder housing. Thus, the secondary cylinder and piston moves with the primary piston. A third hollow shaft is attached to the secondary piston and extends through and is coaxial with the first and second hollow shafts and a bore in the primary piston. In this manner, while the secondary cylinder is carried by and moves with the primary piston, the secondary piston controls the movement of the third hollow shaft.
Alternately, the secondary piston could serve as the holder/insertion tool and the primary piston could perform the later manipulation.
In a further modification, the second hollow shaft is stationary and the first hollow shaft moves on the third hollow shaft.
In accordance with an aspect of the present invention, the cylinders are adapted to be actuated pneumatically or hydraulically, either through external means or by use of the pipeline pressure.
An alternative embodiment of the invention can comprise a primary cylindrical housing having a primary interior volume that is divided into a pressurized primary upper chamber and a primary lower chamber by a primary piston that is adapted to reciprocate within the interior chamber. The primary piston establishes a reciprocating sealable contact with the interior side wall of the primary interior chamber. Attached to the primary piston is an insertion tool that extends therefrom and the insertion tool is adapted with a mechanism for locking the insertion tool in its lower most lock down position. The primary cylindrical housing is removably mounted to a lower lock down end cap that seals one end of a secondary cylindrical housing having a secondary interior chamber that is communicable with a pipeline tee through an opening of the secondary cylindrical housing. When the insertion tool is reciprocated towards the pipeline to its lower most lock down position it can be fixedly locked down to a flush relationship with the lower lock down end cap by way of lock down bolts. Once the insertion tool has been fully inserted into the pipeline to its lower most lock down position and has been fixedly locked down, the primary cylindrical housing can be dismounted from the lower lock down end cap. Removal of the primary cylindrical housing allows the insertion tool to be readily accessed. It is at this point that a secondary piston disposed within the secondary cylindrical housing which divides the secondary interior chamber into a secondary upper chamber and a secondary lower chamber can be reciprocated toward the insertion tee of the pipeline. The secondary piston has a telescopic extension attached thereto that is coaxilly about the insertion tool. The telescopic extension is aligned such that it can be inserted through the opening of the secondary cylindrical housing into the tee of the pipeline. This embodiment allows for a two stage extension into the pipeline system and also allows for a portion of the mechanism specifically the primary cylindrical housing to be removed such that the insertion tool can be readily accessed for further operations.